Launch SecurityHub fragment on SECURITY_SETTINGS intent when available.

Test: atest SettingsUnitTests
Test: adb shell am start -a android.settings.SECURITY_SETTINGS opens
SecurityHub screen (when SecurityHub enabled)
Test: assistant opens SecurityHub screen (when SecurityHub enabled) when
given instrucion to "open security settings"
Bug: 183930061

Change-Id: Ie8fcb2f2dce4cd0a2a84c6cd21a0a1c0b2b3665e